Actually, no. In this case, I don't think it's about 'good enough', in that way!
I spoke to an associate professor that work with cognition some, and she talked about that humans are likely not meant to have very good memory.
Humans process a lot of the stimuli they take in for a long time (don't know if that's the same as low latent inhibition, but maybe), and often, when eidetic memory is present in a person, they are pretty much screwed up somewhere else, she said.
Look at this if you haven't seen it; chimps out-performing humans in memory tests:
http://www.youtube.com/watch?v=TC1nJ61l-h4
I believe it is likely that we might have had a it, or had a very good opportunity to have it, and might have lost it, or never got it, for an evolutionary reason.
(If it's related to latent inhibition, then I may inform you that the mighty Wikipedia speaks about latent inhibition some. There are theories basically about that latent inhibition works like a filter for stimuli in animals and that humans with low latent inhibition either get very creative, or crazy, or both, depending on how their brain processes all the information given to them.
It is also related to explanations for the existence of mental illnesses. People with e.g. bipolar disorder, schizophrenia, Asperger's, usually have lower latent inhibition. So, a little bit of that might produce more creative people, while too much of such traits make people ill. And that might be why people with mental illness keep popping up everywhere. I would put more emphasis on optimization than 'good enough', in this case.)